Timer



May 12, 1925. 1,537,647

- A. w. MCCALMONT ET 51. Y

TIMER Filed May 21. 1923 attain Patented May 12, 1925 UNITED STATES PATENT OFFICE.

MCCAL O T ASSIGNOB TO SAID ianrs'oon;

TIMER.

Application filed May 21,

To all whom it may concern Be it known that we, ALnnRTUs W, Mc- CALLLYONT and. FRANILBBISCOE, citizens of. the United Statesof America, residing at Pontiac, in the county ofOakland and State of Michigan, have invented certain newv and useful Improvements in Timers, of which. the followingis a specification, reference being had therein to the accompanying drawings.

The invention relatesto timers or com.- mutators for internal combustion engines and consists in certain improvements in con struction, which are hereinafter fully de-. scribed,

In one type of the commutator whiclnis in, common use, a roller is journaled upon ,a lever extending outward from a timing shaft; and is yieldingly {held inlcontact with atiming ring consisting of ,alternate ,scgnents of insulating and conducting material. Our invention consists of. an improved construction which is adapted to form a replacement part to be, attached to the timing shaft and to contactwitlrthe timing ring and by our novel arrangement of. the ,parts, we have obtained adevice in which the ,tirningring will have a much longer ,life ,than with-the constructions. heretofore used.

, Tnthe drawings Figure 1 is a transverse.sectionoof the commutator on the line 11 of Figure A; and

Figure? is: a sectional planwiewvthereot on the line of Figure .1.

1 represents a'rotatablc, timing shaft suitably journaled in an engine casing 2 to which is demountably secured a cap 8 containing an insulating ring 4t. Spaced around the insulating ring are the contact points 5 which are inserted in the insulat ing material to form a continuous annular surface 6 and the contact points 5 are electrically connected to binding posts 6 ar ranged on the periphery of the cap 3 but in sulated therefrom. The construction, as thus far described, has been used on an engine of well known make.

7 is a sleeve suitably secured to the shaft 1 and having a boss 8 provided with a bore 9, the axis of which lies in a radial plane and forms an angle with the plane of the timing ring 4, preferably 45. The sleeve 7 is preferably die cast and provided with a steel thimble 10 within the bore 9. This 1923. Serial No. 640,537.

thimble contains an annular bearing surface. 11v in which is journaled a hollow pin .12 having a coiled spring 13. arranged. longi: tudinally thereof and abutting at its, inner end against a ball 14. A retaining pin 15 is inserted radially of the boss 8 and engages an annular slot 16 in the pin to allow a limited longitudinal movement of the pin within the thimble.

17 is a cone shaped member which iseither integral with the .pin 12 or secured to the outer end thereof by suitable means, such as a screw threaded connection, the .outer surface of the cone forming a contacting surface for engaging the timing ring 4. Prefeigably, the cone angle is such that a line contactis formed between the conical surface and the timing ring. The inner surface 18. of the cone shaped member isalso conical and the sides of the.,cone are sufficiently long to overlap the outer end of the thimble 10, For this reason, any grease from within he thimble, which might be .thrownoirt ward by centrifugalforce, is collected within the conical member and is available for the lubrication of the pm by capillary action,

Vith the construction as described the cone shaped men ber l7, hasboth rollingjand slidingengagement with the timing ring at andthe spring 1 3 yieldingly holds the memher,,in contact, with the. ring, at alltimes. Rotation is permitted since the pin 12 fis ournaled[within the thimble and this rotation is not retarded :by the coiled spring because of its engagement with the ball 14.

e have found that this construction of timer is much inorc satisfactory than the commonly employed roller type for it does not have the same tendency to mutilate the ring. This is due primarily to the fact that the contacting member cannot respond as quickly to any irregularities in the annular surface because of the angular arrangement of the pin which eliminates the pounding action and the uneven wearing resulting therefrom. Furthermore, a better electrical contact is obtained due to the combined sliding and rolling action of the contacting surfaces.

Vhat we claim as our invention is 1. In a timer for internal combustion engines, the combination with a ring having alternate segments of insulating and conducting material, of a concentric rotatable shaft, an arm mounted upon said shaft, a contacting member journaled in said arm to rotate about an axis transverse to, said shaft and inclined to the plane of said ring, a coil spring arranged between said memher and said arm to yieldingly hold said member in cont-act with said ring, and a ball between said spring and said arm.

2. In a timer for internal combustion engines, the combination with a ring having I alternate segments of insulating and conducting material, of a concentric rotatable shaft, an arm secured to said shaft having a bore extending transversely thereto and at an angle to the plane of said ring, a hollow pin journaled in said bore, a coil spring having one endwv'ithin said hollow pin, a ball forming an abutment for the opposite 7 end of saidspring, anda head upon said hollow pin yieldinglv held in contact with said ring by said coil spring.

3. In a timer for internal combustion 611 11188, the combination with a ring having alternate segments of insulating and con ducting material, of a concentric rotatable shaft, an arm secured to sald shaft, a member rotatable about an axis transverse to spring and said arm.

said shaft and at an angle to the plane of said ring, a spring for .yieldingly holding said member in contact wlth said r ng, and

aball between one end of said spring and said arm to allo'w free rotation of said spring with said member.

4.111 a timer for internal combustion 5. In a timer for internal. combustion tures.

engines, the combination with a ring having alternating segments of insulating and conducting material, ofa concentric rotatable shaft, an arm upon said shaft havinga bore therein, the axis of which forms an angle of.

with the plane of said ring, a pin journaled within said bore, a hollow cone upon the end of said pin forming a line contact with said ring, a spring between said pin and said arm for yieldingly holding said hollow cone in contact with said ring, and a ball between said spring and said arm to permit free rotation of said pin during the rotation of said rotatable shaft.

6. In a timer for internal combustion engines, the combination with a ring having alternate segments of insulating and conducting material, of a'concentric rotatable shaft, an arm "upon said shaft having a bore therein, the axis of which extends transversely' to said shaft and at an angle to the surface of said ring, a pin journaled in said bore, a conical member upon the outer end of said pin arranged to form a line contact with said ring, and afspring between said pin and said arm for .yieldingly holding said 'conical member incontact with said ring. '7 V 7. In a timer for internal combustion engines, the combinationfwith a ring having alternate segments of insulating and conducting material, o f'a concentric rota-table shaft, an arm upon said shaft having a bore therein, the axis of which is transverse to said shaft and at an angle with the plane of said ring, a pin journaled in said bore, a

conical member mounted on said pinto form a line contact with said ring, said conical member being hollow to form an annular space for collecting lubricant to lubricate the bearing for said pin, and means for yieldingly holding said conical member in contact with said ring. I I

In testimony'whereof we aflix our signa- ALBERTUS w. McGALMONT. FRANK BRISCOE. 

